The invention relates to a fluorosilicone antifoam and, more specifically, to a fluorosilicone antifoam that exhibits an excellent and durable antifoam activity on the foaming of aqueous or organic solvent solutions in which a silicone surfactant or fluorosurfactant is dissolved.
Compared to nonsilicone antifoams such as alcohols, esters, mineral oils, and synthetic oils, silicone antifoams exhibit a superior antifoam activity at smaller additions and as a result are widely used for defoaming and foam suppression in foaming-prone industrial processes in waste water treatment, dyeing, fermentation, the latex industry, the cement industry, the paint industry, the adhesives industry, the petroleum industry, and so forth. These silicone antifoams generally take the form of an oil compound whose base components are principally dimethylpolysiloxane and silica micropowder or an emulsion in which such an oil compound is dispersed in water along with a surfactant.
However, a drawback of these silicone antifoams is their very weak antifoam activity with respect to the foaming of aqueous or organic solvent solutions in which silicone surfactant or fluorosurfactant is dissolved. In response to this, Japanese Patent Publication Number Sho 35-12564 [12,564/1960] has proposed an antifoam based on perfluoroalkylsiloxane, but this antifoam does not have a completely satisfactory antifoam activity. Japanese Patent Publication Number Hei 2-85 [85/1990] teaches an antifoam that is based on a perfluoroalkyl-containing organopolysiloxane that also contains specific functional groups. However, this anti foam is effective only against the foaming of organic solvent solutions in which a fluorosurfactant is dissolved.
Silicone antifoams consisting of silicone oil and hydrophobicized microparticulate silica have also been proposed (Japanese Patent Publication Numbers Hei 4-42042 [42,042/1992] and Hei 4-42043 [42,043/1992]), but this type of silicone antifoam does not develop a satisfactory antifoam activity.